Kikusui PWX750ML, User Manual

Page: 59 / 110

PWX
59
3
External Con
trol
Controlling the Output Voltage
This section explains how to control the output voltage using an external voltage (Vext) or an
external variable resistor (Rext) of approximately 10 k
Ω
.
If no load is connected, it takes some time for the output voltage to decrease.
Control using an external voltage (Vext)
p.40
To use an external voltage (Vext) to control the output voltage, set the CV control using an
external voltage or an external resistance in the CONFIG settings so that external voltage con-
trol is enabled (CF06: on).
The output voltage (Eo) varies in the range of 0 to the rated output voltage (Ertg) when the
external voltage (Vext) is changed in the range of 0 V to 5 V (CF07: Lo) or in the range of 0 V
to 10 V (CF07: Hi).
External voltage (Vext) connection
Use a low-noise, stable voltage source
for Vext. The noise in Vext is multiplied
by the amplification factor of the
PWX750ML and appears in the out-
put. Therefore, the output ripple noise
may not meet the specifications of the
PWX750ML.
To reduce the influence of noise on the
output, connect a 2-core shielded wire
or a twisted-pair wire across Vext, and
keep the wire as short as possible. If
the wiring between the PWX750ML and the external contact is long, it becomes easy for
noise to influence the operation of the PWX750ML. Even if you use cables that are designed
to suppress noise, the PWX750ML may not operate properly.
WARNING
Risk of electric shock.
• The insulation of Vext or Rext and the connected cable must be greater than or equal
to the isolation voltage of the PWX750ML (±250 Vmax).
• When using shielded cables for the connection, protect the uncovered sections of
the shielded cable by using insulation tubes whose withstand voltage is greater than
the PWX750ML’s isolation voltage.
See
External voltage (Vext) 0 V to 5 V (CF07: Lo) External voltage (Vext) 0 V to 10 V (CF07: Hi)
Eo = Ertg × Vext/5 (in V)
Vext = 5 × Eo/Ertg (in V) Eo = Ertg × Vext/10 (in V)
Vext = 10 × Eo/Ertg (in V)
CAUTION
• The signal cable may burn out. Do not connect the Vext output, that is, leave it floating.
Risk of damage to the product.
• Pay careful attention to the polarity of Vext.
• Do not apply a voltage of 10.5 V or greater, or a reverse voltage across the external voltage
control pins.
• When using the optional isolated analog interface, do not connect anything to pin 22
(VPGM) of the J1 connector.
2-core shielded wire or
twisted-pair wire
Vext
+
–
Output terminals
J1
22
23
PWX